Characterization of Solanum chomatophilum resistance to 2 aphid potato pests, Macrosiphum euphorbiae (Thomas) and Myzus persicae (Sulzer)     

Julien Pompon  Dan Quiring  Philippe Giordanengo  Yvan Pelletier 《Crop Protection》2010

The aphids Macrosiphum euphorbiae (Thomas) and Myzus persicae (Sulzer) (Hemiptera: Aphididae) are responsible for yield reduction in potato (Solanum tuberosum) production by direct phloem feeding and by spreading viruses. Breeding resistant traits from Solanum chomatophilum into the potato germplasm provides alternative means to control aphid infestations. Integrated pest management strategy, using plant resistance, benefits from the characterization of the resistance and of its impact on aphid biology. Our objective was to characterize the resistance of S. chomatophilum by assessing the effects of accessions, plant parts on aphid performance, and by assessing the impact of the resistance factors on different aphid developmental stages and on alate morph production. Detailed aphid performance was obtained by measuring fecundity, survival, percentage of nymphs that reached adult moult, and population growth using whole plant and clip cage experimental designs. Accession and plant physiological age, but not aphid developmental stage, influenced all life-history parameters, except for alate morph production which was not induced on the resistant accessions. Plant part influence was independent of plant species and accession. Both experimental designs resulted in congruent resistance levels at the accession level for each of the two aphid species, supporting the use of any of them in S. chomatophilum resistance screening. PI243340 was resistant to both aphid species, while PI365324 and PI310990 were also resistant to M. euphorbiae and M. persicae, respectively.  相似文献   

Clarification of veterinary dental nomenclature     

Bellows JE  Dumais Y  Gioso MA  Reiter AM  Verstraete FJ 《Journal of veterinary dentistry》2005,22(4):272-279

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Dentistry: Creating a Profit Center — Blueprints For Your Bottom Line          下载免费PDF全文

Yvan Dumais 《The Canadian veterinary journal. La revue veterinaire canadienne》2001,42(8):637

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PrP genotype frequencies of Quebec sheep breeds determined by real-time PCR and molecular beacons          下载免费PDF全文

Yvan L'Homme  Anne Leboeuf  Johanne Cameron 《Canadian journal of veterinary research》2008,72(4):320-324

The allele and genotype frequencies of the prion protein gene (PrP), known to have an impact on scrapie susceptibility, were determined by real-time PCR for 500 Quebec purebred rams. Molecular beacons were very efficient in discriminating the 5 alleles investigated. Polymorphisms at coding positions 136, 154, and 171 of the PrP gene were analyzed using 3 separate real-time PCR reactions and a total of 7 molecular beacons. A total of 4 different alleles (ARQ, ARR, AHR, and VRQ) were observed at different frequencies among the 7 breeds of sheep investigated. Results show that more than 50% of the rams in every breed carried at least one ARR allele, which is considered the most resistant to scrapie. The susceptibility ARQ allele was also present in every breed and together with the ARR allele, they were the most frequent alleles found in Quebec rams. The VRQ allele associated with the highest susceptibility to scrapie occurred in 5 of the 7 breeds, although at low frequencies. Overall, the results indicate that the frequencies of PrP alleles and genotypes in common breeds of sheep in Quebec make it feasible to reduce scrapie risk by selective breeding.  相似文献   

Protein and lysine requirements for maintenance and for tissue accretion in Atlantic salmon (Salmo salar) fry     

Tarik Abboudi  Muriel Mambrini  Yvan Larondelle 《Aquaculture (Amsterdam, Netherlands)》2006,261(1):369-383

Available data on the quantitative requirement for lysine (Lys) in different salmonids show much variability. So far, there are very limited data on the maintenance requirements of indispensable (I) amino acids (AA) in fish. In the present study, we determined simultaneously the Lys requirements for maintenance and for protein accretion in Atlantic salmon fry by adapting a protocol established for the piglet. Groups of fish having an initial body weight of 1.5 g were fed for 28 days on isoenergetic diets with increasing nitrogen (N) content supplied by cod meal and a mixture of crystalline AAs (50% of total dietary N). Except the protein-free diet (PF; 0.2% dry matter (DM)), the N content of the other diets was either low (2.9% DM), medium (6.2% DM) or high (8.5% DM). Two types of diets with the same N content were formulated. The AA pattern of three control diets was based on the AA pattern of the cod meal protein. For the other three diets, Lys·HCl was totally omitted from the low-N diet (LPD), and 50% of Lys·HCl was removed from the medium- and high-N diets. After a 28-day feeding trial, carcass N and Lys gains were estimated. N and Lys requirements for maintenance and for growth were calculated regressing daily N or Lys gain against N or Lys intakes. The daily N requirement for growth above maintenance was 3.05 g per g protein gain and for maintenance it was 54 mg kg body weight^− 0.75. From the regression between protein and Lys intake, we calculated that for the accretion of 1 g body protein, the dietary Lys requirement was 152 mg, and that the Lys maintenance requirement for zero N gain was 20 mg kg body weight^− 0.75/day. This last value is higher than the previous estimations obtained for rainbow trout and could be explained by the lower body weight or age of the fish used here.  相似文献   

Growth of early juvenile winter flounder (Pseudopleuronectes americanus Walbaum)     

Benjamin de  Montgolfier  Céline Audet  & Yvan Lambert 《Aquaculture Research》2005,36(16):1595-1601

Metamorphosis is a critical developmental stage in marine fish species, but mortalities are also elevated at the settling phase. Our objective was to evaluate the effects of different rearing systems and larval diets on survival, general condition and pigmentation of newly settled winter flounder (Pseudopleuronectes americanus) juveniles. At settlement, winter flounder juveniles were reared in two different types of tanks (plankton kreisel and rectangular raceway). The early juveniles were followed for 1 month and their condition was evaluated using biochemical indices. Juveniles did not show signs of fin rot and pigmentation was well developed, but they had different RNA/DNA ratios. This study highlights the fact that rearing conditions at the onset of the juvenile stage may be critical for successful juvenile production.  相似文献   

A concise overview of national nutrition action plans in the European Union Member States     

Lachat C  Van Camp J  De Henauw S  Matthys C  Larondelle Y  Remaut-De Winter AM  Kolsteren P 《Public health nutrition》2005,8(3):266-274

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Mineral Oil Inhibits Movement of Potato Virus Y in Potato Plants in an Age-Dependent Manner     

Fadi Al-Daoud  Manphool S. Fageria  Jianhua Zhang  Sébastien Boquel  Yvan Pelletier 《American Journal of Potato Research》2014,91(4):337-345

Potato Virus Y (PVY) is one of the most devastating pathogens threatening potato production worldwide. It is a RNA virus that is disseminated by aphids in a non-persistent manner. Regular application of mineral oil on potato fields is known to reduce the number of PVY-positive tubers in post-harvest testing. The mechanism of this phenomenon is not well understood, but it is hypothesized to influence the virus-vector-plant relationships. Here, we present data from greenhouse and field trials that shed light on the effect of mineral oil on local and systemic accumulation of PVY^O in susceptible Shepody and Russet Burbank. The data suggests that mineral oil did not influence PVY^O levels in mechanically-inoculated leaves nor tubers of plants with a secondary infection. However, a reduction in systemic PVY^O levels was observed in mineral oil-treated older plants but not in younger plants, suggesting that mineral oil inhibits PVY^O movement in an age-dependent manner.  相似文献   

Olfactory perception of cysteine-S-conjugates from fruits and vegetables     

Starkenmann C  Le Calvé B  Niclass Y  Cayeux I  Beccucci S  Troccaz M 《Journal of agricultural and food chemistry》2008,56(20):9575-9580

Volatile sulfur compounds have a low odor threshold, and their presence at microgram per kilogram levels in fruits and vegetables influences odor quality. Sensory analysis demonstrates that naturally occurring, odorless cysteine- S-conjugates such as S-( R/ S)-3-(1-hexanol)- l-cysteine in wine, S-(1-propyl)- l-cysteine in onion, and S-(( R/ S)-2-heptyl)- l-cysteine in bell pepper are transformed into volatile thiols in the mouth by microflora. The time delay in smelling these volatile thiols was 20-30 s, and persistent perception of their odor occurred for 3 min. The cysteine- S-conjugates are transformed in free thiol by anaerobes. The mouth acts as a reactor, adding another dimension to odor perception, and saliva modulates flavors by trapping free thiols.  相似文献   

Development of a 16S rRNA microarray approach for the monitoring of rhizosphere Pseudomonas populations associated with the decline of take-all disease of wheat     

Herv Sanguin  Lionel Kroneisen  Kevin Gazengel  Martina Kyselkov  Benoît Remenant  Claire Prigent-Combaret  Genevive L. Grundmann  Alain Sarniguet  Yvan Moënne-Loccoz 《Soil biology & biochemistry》2008,40(5):1028-1039

So far, the analysis of microbial populations associated with wheat monocropping-induced decline of take-all disease (Gaeumannomyces graminis var. tritici) has focused mainly on culturable biocontrol pseudomonads. The objective of this study was to develop a taxonomic rrs (16S rRNA gene) microarray to assess the changes in Pseudomonas populations taking place during take-all decline. The microarray contains 12 probes for five Pseudomonas phylogenetic clusters chosen because they include well-known plant-beneficial pseudomonads. Four of the clusters are within the ‘Pseudomonas fluorescens’ species complex. PCR primers were selected to target these five clusters, and they were validated using 53 pseudomonads belonging or not to these clusters. Microarray analysis of the pseudomonads enabled discrimination between strains from several Pseudomonas clusters. Rhizosphere samples were collected from field plots grown with wheat for 1 (low level of take-all disease), 5 (high level of disease) or 10 years (low level of disease, suppressiveness reached). Microarray data could distinguish Pseudomonas populations from some of the wheat plants grown in the same plot. When comparing treatments, there was a difference between years 1 and 10. Cloning–sequencing of rrs enabled to define more precisely this difference by identifying two major Pseudomonas populations, one associated with year 1 and the other with year 10 (disease suppressiveness), which represent new clades within the ‘P. fluorescens’ complex. These populations may be useful as soil quality indicators. In conclusion, the combination of microarray and cloning–sequencing approaches highlighted changes in the prevalence of two major Pseudomonas populations, giving new insights on the dynamics of root-associated pseudomonads during take-all decline.  相似文献